Remove screen dependency from font_render_params_linux

ui/gfx/font_render_params.h

Index: ui/gfx/font_render_params.h
diff --git a/ui/gfx/font_render_params.h b/ui/gfx/font_render_params.h
index b460c6d88b8b8d549cf20ae9162799176887315b..7a294bdc3cd5b77801bbc51d14240873521d3ace 100644
--- a/ui/gfx/font_render_params.h
+++ b/ui/gfx/font_render_params.h
@@ -108,9 +108,9 @@ GFX_EXPORT FontRenderParams GetFontRenderParams(
 GFX_EXPORT void ClearFontRenderParamsCacheForTest();
 #endif
 
-#if defined(OS_CHROMEOS)
+#if defined(OS_CHROMEOS) || defined(OS_LINUX)

[msw, 2016/04/08 20:42:58]

nit: Isn't OS_LINUX true on OS_CHROMEOS? If so, you can remove the OS_CHROMEOS
check and merge this with the OS_LINUX block above.

[oshima, 2016/04/08 21:28:17]

That's technically true, although it still can be informative.

I don't have strong opinion and will follow the owner's recommendation as there
are other places that have this.

 // Gets the device scale factor to query the FontRenderParams.
-float GetFontRenderParamsDeviceScaleFactor();
+GFX_EXPORT float GetFontRenderParamsDeviceScaleFactor();
 
 // Sets the device scale factor for FontRenderParams to decide
 // if it should enable subpixel positioning.